Piccini A E, Jahreis G P, Novak E K, Swank R T
Mol Cell Biochem. 1980 Jun 18;31(2):89-95. doi: 10.1007/BF00240814.
The size distribution of lysosomes was determined in kidney proximal tubule cells of two mouse pigment mutants, pale ear and pallid, which have an increase in kidney lysosomal enzyme content caused by a decreased rate of secretion of lysosomal enzymes into urine. Both mutations have larger lysosomes when compared with normal mice. However, neither mutant contains the giant lysosomes (up to 11 micron diameter) common to the well-characterized beige mutant, which has a kidney secretory defect similar to the pale ear and pallid mutants. Subcellular distribution studies, performed by the osmotic shock technique, likewise suggested differences among the pigment mutants. A very high content of soluble enzyme, indicative of lysosomal fragility during homogenization, was found in extracts from the beige mutation. By comparation, the percent of soluble enzyme became progressively lower in extracts of the pallid and pale ear mutants and was lowest in extracts from normal mice. All 3 pigment mutants had normal concentrations of osmotically resistant membrane-bound lysosomal enzymes. This indicates that the excess, non-secreted, lysosomal enzyme in all three pigment mutants likely is present in classical lysosomal organelles rather than in other non-lysosomal subcellular membrane fractions. The results also illustrate that mammalian mutants which exhibit lysosomal secretory rates can have strikingly different effects on morphology of lysosomes.
在两种小鼠色素突变体（淡耳和苍白）的肾近端小管细胞中测定了溶酶体的大小分布，这两种突变体由于溶酶体酶向尿液中的分泌速率降低，导致肾脏溶酶体酶含量增加。与正常小鼠相比，这两种突变体都有更大的溶酶体。然而，这两种突变体都不含有特征明确的米色突变体中常见的巨大溶酶体（直径达11微米），米色突变体具有与淡耳和苍白突变体类似的肾脏分泌缺陷。通过渗透休克技术进行的亚细胞分布研究同样表明色素突变体之间存在差异。在米色突变体的提取物中发现了非常高的可溶性酶含量，这表明在匀浆过程中溶酶体易碎。相比之下，苍白和淡耳突变体提取物中可溶性酶的百分比逐渐降低，在正常小鼠提取物中最低。所有这3种色素突变体的渗透压抗性膜结合溶酶体酶浓度均正常。这表明所有3种色素突变体中过量的、未分泌的溶酶体酶可能存在于经典的溶酶体细胞器中，而不是存在于其他非溶酶体亚细胞膜组分中。结果还表明，表现出溶酶体分泌速率的哺乳动物突变体对溶酶体形态可能有显著不同的影响。
